SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7593a1f1055ab2e414ffdd0936f4227c415467511a3a279c24286806fc57b606' 
  AND token = 'oTKAzijn1zzt+4NyFj2HpBSJxDqwn5MUxFtNDrlPyow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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