SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '474d9e4db1ee61ae34b3bb569ad4f627aed9dfe4b0d42561811f2a877d2f0ab2' 
  AND token = 'aW7oOei/7BXk+KQNQgxlniuik2mzgS6LPb2cbLGPnUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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