SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8090671f0dd244836eb482748b138d6abe70ff62101c62a2810c98ee18f7fae9' 
  AND token = 'VOn0Go7Svj5kq96zWwfRXx2y6NWTifaDKUcgAdiK3Y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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