SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c59e3212e8fa391e637635be6da050e524423185287ceb7f834e2ed8ff6653b' 
  AND token = 'ZjV/VRTD09yD2nXx2ZBh5plzHodJQWfMGyqFrbmGTy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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