SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '165c550868ec6e3f529322b68f1c2d73d3143782f847ac9a4d1e28bd52f596c3' 
  AND token = 'MXJqBjQPhQmh/r+XrCvOpMGGmwsuadgRws9o0glroUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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