SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf2562cb6fe0cfb3d569ba590779fbeaba7e9f9d441a2b50f0c57d1d49831288' 
  AND token = '+iYLbuGzURF+ZemrZ7aPmmFgudwzjrBIe/38I6aggOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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