SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45be9ed1c2ddc115ec720a0a9ed44b87ec542789ea7e69fdc8dd7ea9924d3993' 
  AND token = 'hjYtDJtphadFqhAShMzPmta0CPZyeoY6nlXrBE02Ni8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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