SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ab84637204ab360a1a26cd81cfb3072354dd414c5918e318edd4058a8f9aa4d' 
  AND token = 'xiKgnuxNM7ZqPCa9DnPsKmfsAPhCg2YjuopA0XlQeK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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