SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88a5db29f730dbe85c661134c1fb55cbe9404d1b4e52ecb6e476a88a41cf2082' 
  AND token = 'g3KmqsqckGY0pSCsLumbvYSULBlQPu8kv8pZX/shN4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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