SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e46b1fa871a031581009006d1d75ceb921e03a25c359a07e84b0fbc784169951' 
  AND token = '+TsSH4rUhbszBqeSFLIg7+4t1GkNtA6jfjXLXbhkFIA=' 
  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"
    }
  }
}