SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ca1025a3734a866c10f6e6c4b304acb14c778347200dfae9fd8dde65ade8c651' 
  AND token = 'V/scec+i332pimLKsjYgvBYzopb/Oo/WdB00Z2cYGZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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