SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57ff57af4c35ae6710e66f23dd3a52181c419935467fd7c9f2d2237c19fd460f' 
  AND token = 'tqvVHOau3w38Mspv7Zi6UoubXegNK14RHp8Ov8msCsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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