SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76ae9e06b1d75e1d2474a5fc90e9bb887d20f452036ebabb5bb7273fe386cf10' 
  AND token = 'X4GOwSKszT9WVvQz9EEqACehgdIOjQBV/EDKIVCLBac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}