SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae6cf6a06583b08a2f2d4d25ec05726bcfaeb789acee477b37580b8fe52c6cc8' 
  AND token = 'Khc89vzzY9nUPkDSNHygUo2PLU0HGSMblSpZXi0Ymzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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