SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e63cbf45e155f701b6c613cf7f3b6f6ad14c62e8dfe3aed8d70dddd84ceab35f' 
  AND token = 'uTahOvJjLB3ZhSjj0vXKfFeaIUh5b5ME9ntXvQBPEsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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