SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc1c2890c7db1f2945d2027b67b9532be4228ec83b969a57824067ff780ea90c' 
  AND token = 'pz0aCnxexALyDf9n7hd3v7WXTWzwfOqrFHsHwtSwX7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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