SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33bf448a8cab3337a7efc0fa151203e19ed0e7d4d167ecddeeeea290b6cf485c' 
  AND token = 'Cl29dnh2GxqsFM74qf+VsPKlpqDyp6gdtqfSSYPQG2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}