SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49cbdd91ba0b5c9e2f7b90f894cee4621fbce3e6f38ebdfc2461de8cc25bb213' 
  AND token = 'u4roWpyJ3uE2GCidtMSKbd+bsppB80OIu/6Hpp4/cU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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