SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25acd80cc78138e025847d88f7fea659d02829829ed3d61e8ea3544a62f3208f' 
  AND token = 'w8BfOH31drXRNm8DBNWOqfzK8/CpZcyPtdGZQqNFd+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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