SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3888cb807c1e17bbe504e386d28c797da9e0cbd7c2166d9585af9d7e73f4c4ef' 
  AND token = 'dEjWvoDIWIwvtgtv2Z02lEB1uXUZqoXfPUigY60PYOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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