SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34e6f5637f0d04f118e7da0de84fa31b50850d4f8c1e1f8166ab36be7089f6af' 
  AND token = 'ecT5fj0wO3oW7m9KRrpiFVE9eNuCTIFEVcpDcSbz61s=' 
  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"
    }
  }
}