SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ddc63c3b0e1a1e27ddd86dafe6c1335fe66d4130451abeb98575cdb0119696a' 
  AND token = 'qSi+ccFQNnoZwYzumc6U47poJwGLDmgzJteNsJQgjR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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