SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79771bd1a13cca74ef4e8a21f8bc76ffdc3637d46b23a55a762a219cea64e390' 
  AND token = 'IoSw6yKREzPmLMEzzqaLq9QAcL3oOrI2NruV5W01YBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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