SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f08636f7c288c1ba63c12d3fe2e04b2b26b548ce5342acfad59544543f0b151' 
  AND token = 'CpMRzehTkosYXlNx/bRGLF+HD1uXdAix9Ag5YThqAVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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