SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f3a1f8bdfd37dcf0a5051a7c6d28ec8b7468d9b547073762243a87a8a4b6754' 
  AND token = 'G4TvdDDEIbBKENpQFJoJQUTRpO6NU8qXYaHoF35iXZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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