SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '31f24059f947e0e61f9bad75b002535b3ccf20b2dd46bb19f77059a9963c279e' 
  AND token = 'srLo3dpBQFcpP+pBKbeOZJNwpX3ntWSqYXKygdoAT2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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