SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f0f9f4951476416e261626fec630c6e2a4e2a03c1053e0b8abd5254b80335a5' 
  AND token = '7xQVsrXcY6aLKOFCSC+tn3CnBn9eQJLETUBtJ7j83+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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