SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e467b7738ad6cb556cc2f0a9e8eccf5c3c622d2f52a9b507f20610b79d09da5c' 
  AND token = 'bgThqH7PLVIeLjOKFPpsMcgn1Ftl2QReBfz5ieV71G4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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