SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceb951658e45f6aa0838085fcb4e01cd0ac9d5326409635acc02412521fe5e6d' 
  AND token = 'RPJKI4n6Io8r5qKArGrrhpxFXPzA6QHHQXF2jKFopB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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