SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75121603c35f76fc3e4dfb18b07ea313bd98bec180117735e8a134c44eeed1c1' 
  AND token = 'DWP2EoRwMYLeWvi2+qT7k9nxf2Ju4MgmUPAszJbSuTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}