SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8d08f1afd329d8de7d17562f7bf6ea032955a906aabb77626ab9d00ffcdde19' 
  AND token = '4CCGlBEUkm4gmSs/Dmfelp/vwmPRBDUdFtBFtQGN9ZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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