SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5a745c7039770e31bf1142e21f3c985113d121b85d529c692c88998627aebee1' 
  AND token = 'B3XN92zoSg90FpLOsoSaTDFFvVFesbaqMRsEKmSoGm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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