SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5eea084a081275c8ab8bc61f1c232b859f69ccf1ec746e4e4095c2d6051ac55' 
  AND token = 'PRngStYRbqhGUimSf1gh6AOHbP7s3Z96wcAesxXw/N8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00119

JSON explain

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