SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b68a84f3cc35ca3d17bc285db047c65c0f5c6ff113e9bca907ab5ad7bd22e24' 
  AND token = 'oU+RH5edlB+AsAU3KrB5xj+yFvpjBxufwBdaUPTGL+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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