SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4327cafae9d17838e4a2988647742da7a650654cb4ca4f8534da1760af828193' 
  AND token = 'Xv+2+u7/mHaG0uUtdpWTPnuNLDMBcHp+O+rGZIwIeK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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