SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8979fc2153ff1a1c64119fd56dfce81d6edfbb0ff24831bd62ca857b52357f21' 
  AND token = 'BH+neCnEgaqAENV5HRCWHAbojLZrXfc+4xaJZW17dm8=' 
  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"
    }
  }
}