SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c88b3672517bef3cb3e4037b60120d13c7526f972ffa6a745418a4a03f53586' 
  AND token = 'HEVO9UuMIdzAJPTk0V0cj+NKFN2Qjyw22hKzngT098s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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