SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '280aad1fc1fe790ea9603ceacd789bf5ecc415931b3663efbaf23bc07bffa836' 
  AND token = 'I7bPUUWBQCDkam8bvXfkTIuoM/+1q4oLrlprtsIJV08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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