SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ce7624d1e8bd93af3f671d674a2a275cf29fc81cf07a11a8fa5f0f3c7c460bf' 
  AND token = 'whbtkNeMgQwDc1TRnCnUwkOwTy2XzN4zV+IcksiZIK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}