SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e632bae59263221a77a848280782efde436cac343d40a7469457f9f953fea8d1' 
  AND token = 'yTmbIfAMvnO3Btdb369UXndFBd7Ie/67YorSSRTqnzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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