SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e60efc892baae730f342a41b60144a5a29e3a0556584b6a27d0f49e6b1c1ef4' 
  AND token = '8/ROfLok8ncPMpHAI9TsGLbSHqYbnUcCQafB3wL7chE=' 
  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"
    }
  }
}