SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9eb3f957dce075545e10f5fa6fd83cc0a27159dada78b07f66268b8b8fefbf3' 
  AND token = 'yBWaOkzbEQr2D04aPdoepL+TsBPJEoJqVS7QeBN63vQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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