SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '657d45a8b33102d41e1832885456c560a8e9aa0e33630675c3978ac8dc795674' 
  AND token = 'D8B/IeyuC+D+mwSHrEm0wyCtLEffkQJzopljasIQhrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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