SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5844a57a72bedd5dc888c814cb25f374bfd3e84db4d2014f2a809b8f769ec06' 
  AND token = 'ZrTE1DkULfYBWG2iAzKoKHz6Txmm5ZxQUmLJYgXZ1bY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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