SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1c94045afa8864404c55530cacb1eb34e6c89c9b81b0325c9a62a1665eae2921' 
  AND token = 'QBvxGjrnBJigHXae4ph+c2RCWZXVKuFgXHMggUqkSZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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