SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a1ab5dcf0a4d7358be0af5f2b5f2c2baffbb15526705443ce764de37599baca' 
  AND token = 'ADWVP0AkrfSyR96ZPLcQTtqFokmfrZrzCdniLrr6hnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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