SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe3f38f4649c6de9a268d1cd8ffe1e74ed105f91e65848f779928f6d86d00d5a' 
  AND token = 'q8E0lPTpKlGaCK9sQk8R4Y6IMowZC4LbxVzQ8hCTKj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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