SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '766d009eb55f4dafef6191dfbceb51374bcc57afa4bf686184ed2a26c0f1def9' 
  AND token = 'FkiTqQQmZkQhKpHA62xaRDRuFfNsr+AMLiFtYVJsE8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00097

JSON explain

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