SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '588c000cfcb18648a2f3b46413da09aba01fe55a125e82151eefd22c499a9ff0' 
  AND token = 'FU70j6Eufkeq3pYX3XgoXBgkmnQmUG6hoJmp88kBvjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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