SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17e347ef615dcc1a401ea77cf6f26114f0e1989184735f60ab74cc888968112a' 
  AND token = 'VXp3T3NByjToyFLLVr6J1G7jLwkFqNnUxtPDf8fMB74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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