SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37fd069bb8bc1dd1e78a1af247c3bb9e2f3209f2e593a205d43a66261260333e' 
  AND token = 'SbmQnvsCjQxHVD9iOoO44y0ufQlFn+tm9NgzZ3mkWxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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