SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a811cb425429e6aee20801864c9cd6ecc1f3ee9a2bf6774ecf773eeaed0016c' 
  AND token = 'EDPY4jAsNgNBEWqp7cPt2HaVy9anLW3c/Vs2o4X/VlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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