SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f5a8d21793cfe513190575036686c9f30dae210e7acf07b675d7cacd082c26d' 
  AND token = 'Zc3zLA+dGe1pwPnw50fKrai1Bq9OZ2oJx/mVslITocs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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