SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ca4bac1252cd9ee94a181ee544648d90912706d9cfcd1152d2b15a4d544150f' 
  AND token = 'Zv66isRFoOVlK4H5cKvUwEN5p63K+vZexW3pjTRPzv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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