SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd482f92833fc0dde72b111f78a7873d6bb8dc63b959a569bcfe39bafd067f3b6' 
  AND token = '1NJSFQ2UaFQjszIWEprXWFsyyOLHCxwvEJpnTZU4tLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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