SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bd5dbaba4236589d6178ca94a135fffd91678f5d27df623aa8eb0db70eec4b3' 
  AND token = 'AdtlkMqEW6/fJ9fv9I4IH/tE/ZJ1Wkx7PlbZiPzuHA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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