SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c627707b4f654538c8099270b268df9a06173d8e3e47e9bb5a9b6675bc6107a1' 
  AND token = 'cSI7xyVnG4DqeNnFrVuPtYHiDASAFZMvNqiRD0vWR2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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