SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42fc37091d2283c7195124b3f3b35f19fc453675b9179c68e22944a45c75a13a' 
  AND token = 'ONbTHlsm7jlNPqD7znr7/OruGlKLAE7Vr6hmG/XbYtY=' 
  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"
    }
  }
}