SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '731aa1ab196f97ba3840d28abbf9ecc931cd9616eb8be2261ea679fc3f162fe4' 
  AND token = 'tMOgiq9ngJVnMzen2XDr7CTOhH3fgld7EDwxibFeCgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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