SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1626bea22f90b4b6f1729501dad0268e9862ed2603d4d6992f1d310a938e1f0' 
  AND token = 'vWEcWfQjNyTVTcPX6BJJaIaeHkbQMUsxiEHX8hUkvzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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