SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '860bb509e159bd168ded0ab6d06893ced1df6d394b78d141c2403da14f0bd0f8' 
  AND token = 'kEr56Qw/6DDpUtakXApaJcxUBPhmJrUSXf9TVAVf4DY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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