SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5aa1fa43132b30ae6894aad20c0442d42daf8d0e821fa08ddaa7d084c96fd22' 
  AND token = 'CrZtsni+An5IC4iRZ3atvEZRJ3LVbFY1NEzSHuUnc/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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