SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3380ffa199e8052525120aef389eed0183e001107b49fc2fc84e4791b8610170' 
  AND token = 'sqFt1zk4Ikvms7V2Bv6M/t+MKow5BNGnWAl+S9QgQ4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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