SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f65cec2e4da77a7d491a87561402a4072d501e3290e53ca9f2a44ff7f7842fb' 
  AND token = 'gmCgZVzXxmkFBmp0Km0G/FRhXFE6yA6AG8dQsJ4wHO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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