SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2952640a6404eb77c26250c6aa99e29cb97c66d9dcab887782b63a69e18d473e' 
  AND token = 'jFhK07ksQsYOXVSTY7GciQufqTmGti5KGYuZDeQFdkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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