SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8dc84c16cf64213b38e6e4c673684db9a1436e1b95086667ab19c3a8397e3a7' 
  AND token = 'Ak/4xk6yE6ECvvDycW6o5Enk+2KS0hNTYA9Mb69UMak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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