SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de4f219bfdfa79fcfe7b3c4a20b54413472e9ec226e904001c3b478b67128664' 
  AND token = 'fg7BeUAld61CJoChSjZPdDPtzGnUcKIuZ/V56eXAvVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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