SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'babaadb97249fae36b8b333bcbbf75baba663427b75784bbd0bcaa06e0afab04' 
  AND token = 'xtWBjpRJGt84/4ZiPfzRQeaaTfQNutLhdjvTSrHxKPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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