SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c355225689af1994bc3be9ccc7d4d06943c714b7485d5b32fc773dc6ee7384a8' 
  AND token = 'A+YkB4GL0CYr+HVnk4RDAsqX2IjFVvsEJhFQS7O+hUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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