SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c11ae07f09f6373c3e666c0970eaf990a1db2cfbe0d52d856b065dc7954981a' 
  AND token = 'UvY4uK60jHJiFzgJ9QrwD7Pz6zLUCpNpUy5aEDR2Uqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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