SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d96ba81cff853e44b22baf361182004fd19346e249757f7b690dbf283e739fc' 
  AND token = 'UBTBhbUOlerTgtX2MSlIK/KlnAIRr5XfWosHUSXVyV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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