SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d8aa76baeaae67630eb0ec0af1a7f5cee9bb0bb5cea8baf9956e273dcc937f3' 
  AND token = 'ZanWaa9lrVfgjECOS4/wllK3esJ/07fKiZOOfsRsGzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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