SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccd5885de04cf0e1c420a08324e386a6b8ba0125b7293638708451084c4250da' 
  AND token = '0AKxgKzH2bHjAEQgwOwxyzE+BZ4B6leCjYqS/SI27wQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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