SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a001f3817117dd283d7313126d91b4b57dcbf27cf8c6b39f6891f7f7e7bf8707' 
  AND token = '0OM7qICl9UCNs8NuJ3aZ+Qi2ARS61cyDsIMyRnB2380=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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