SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '93aae5030c6c2ae43364ce48a000eb83cec171a0ea5f08f2896e0db882f45692' 
  AND token = 'e3PYMY9LdAU1W6ScdkyeAVBEmfBtP0ldDavw24lnzRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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