SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9ced818152b4378fac05c8b6b06bb545ad026d319194ec490117c8cb35a746b' 
  AND token = 'FDv9YY9JriMI+R6zyxGkoPwLtgIV+S6v9/rfEHJ03xM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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