SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5297703547eb5aef9af9a0ec3ed1bef26159ce452468abbf019b436adb761099' 
  AND token = 'X2n5J2vIIudaAx1BT3zVP+hjnuTh+/ge6K8pbkrsKQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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