SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81d31156bae649dd6daf0c990a4db2a0882c8af4d6deeabd6939558ba1c4cc94' 
  AND token = 'q3zZPD1kLNS1zXB8HFj1dzs3g0UDDM5o1xuyUB9vK/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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